The present invention relates to memory module devices including their formation and use in other devices such as memory cards and computers.
Conventionally, in a memory module 101 that is used for a memory card and a computer and the like, one or more memory chips 103 are mounted on a surface of a circuit board 102. FIG. 11 is a perspective view showing an aspect of a conventional memory module 1. As shown in the figure, at an edge of one side in the longitudinal direction of the circuit board 162, contact terminals 104 that have been conducted with (the respective terminals of) the mounted memory chips 103 are arranged. Further, the contact terminals 104 are provided on both sides of the circuit board 102 such that they are facing each other through the circuit board 102 (a back side thereof is not shown), and the contact terminals 104 that are facing each other through the circuit board 102 are designed to conduct. Further, the electrical connection of the contact terminals 104 that are facing each other through the circuit board 102 is implemented by a through-hole (not shown) provided in the circuit board 102.
Then, the above-described memory module 101 is installed in a connector 106 provided in a main board 105 that constitutes a memory card and a computer. FIG. 12 is a side view showing a state of which the memory module 101 is installed in the connector 106. As shown in the figure, on a surface of the main board 105 a plurality of connectors 106 are provided, and by individually attaching the memory modules 101 to the connectors 106, it makes it possible to pass a signal from the main board 105 side to the individual memory modules 101.
In the conventional memory module 101, if the number of attachments of the memory modules 101 is intended to be increased for a purpose of increasing the memory capacity, then the number of connectors 106 must be increased, thereby the mounting area increases, and as a consequence, there is a problem that it is difficult to achieve miniaturization of the memory card and the computer itself.
It is an object of embodiments of the present invention to provide a memory module structure which minimizes the need for a large mounting area in a device while maintaining a general memory module versatility.
It is another object of embodiments of the present invention to provide a body of memory modules for installation into a memory card and/or a computer.
It is yet another object of embodiments of the present invention to provide a stack including a multiple number of the identical memory modules, in which a necessary signal can be connected to all memory modules in a simple structure.
These and other objects may be accomplished in certain embodiments by providing a memory module including a circuit board on which a memory chip is mounted and a plurality of connection terminals which are provided at locations on both sides of the circuit board for passing a signal with the memory chip through the connection terminals. The connection terminals include a first connection terminal group for passing a specific signal in the memory chip, and a second connection terminal group for passing other signals. The connection terminals of the first connection terminal group are configured such that connection terminals on both sides of the circuit board at asymmetrical locations are electrically connected. The connection terminals of the second connection terminal group are configured such that connection terminals on both sides of said circuit board at symmetrical locations are electrically connected.
Other embodiments include a laminated body of memory modules comprising memory chips and connection terminals for passing one or more signals between a memory chip and a device body, where the connection terminals include a first group of connection terminals for passing a specific signal to a specific memory chip. The first group of connection terminals are facing one another from overlapping memory modules and are electrically connected to each other. The connection terminals also include a second group of connection terminals for passing other signals to the memory chips as common signal lines. The second group of connection terminals are facing one another from overlapping memory modules and are electrically connected to each other, and the common signal lines are connected to the device body.
Embodiments also include a laminated body of memory modules comprising memory chips and connection terminals in which the laminated body is coupled to a device body. The connection terminals include first connection terminals for passing a specific signal to a specific memory module chip. The first connection terminals are individually connected to the device body from a specific memory module. The connection terminals also include second connection terminals that are facing one another from overlapping memory modules in the laminated body. The second connection terminals facing each other are electrically connected to each other as a common signal line, and the common signal line is connected to the device body.
Embodiments also include a memory device comprising a first memory module including a circuit board having top and bottom surfaces and at least one memory chip on at least one of the top and bottom surfaces. The circuit board also includes a plurality of top surface connection terminals disposed on the top surface and a plurality of bottom surface connection terminals disposed on the bottom surface. A first group of the plurality of connection terminals includes first group top surface connection terminals in electrical contact with and located directly above first group bottom surface connection terminals. A second group of said plurality of connection terminals includes second group top surface connection terminals in electrical contact with second group bottom surface connection terminals that are not directly below the top surface connection terminals.
Still other embodiments relate to a memory card, including one or more memory modules having a structure according to the memory modules discussed above. Embodiments also relate to a computer including one or more memory modules such as those described above.
Yet other embodiments relate to methods for forming a memory device. One such method includes providing a plurality of memory modules having top and bottom surfaces and top and bottom connection terminals. Each memory module includes a first connection terminal group including first top surface connection terminals in electrical contact with and located directly above first bottom surface connection terminals. Each memory module also includes a second connection terminal group including second top surface connection terminals in electrical contact with second bottom surface connection terminals that are not directly below the second top surface connection terminals. At least two of the memory modules are stacked so that the top connection terminals from a first memory module are directly aligned with and electrically coupled to the bottom connection terminals of a second memory module.